save workbook as cell contents and as .htm

Could anyone please tell me how to modify the macro below to save the workbook as a .htm file.

The macro below is designed to save the workbook in a directory, in a cell.

Sub SaveWorkbook()

Dim FileCellName As String

FileCellName = Sheets("Test").Range("A1")

ThisWorkbook.SaveAs FileCellName & "Workbook.xls"

MsgBox "CustRef.htm was sucessfully saved"
End Sub
Thanks